Title: ぜんぶきみの性 (Zenbu Kimi no Sei) All Because of You
Creator: 浅月のりと Asazuki Norito
Books: 7 volumes, Aug '20 - Jul '23, Dengeki Comics Next, Kadokawa
A good TSF love comedy. One where the point for the creator was to be able to have both people in the main couple transform back and forth and be happy in all 4 states.
Ryou, the protagonist, is a boy who prayed at a shrine for help getting together with Nagisa, a senpai at the high school he's starting at. Ryou's wish was granted in the form of TSS: a syndrome that makes Ryou switch sex when excited. Nagisa has always had TSS, so the school puts them as roommates. Ryou also joins Nagisa in working at a cosplay cafe.
Because Nagisa grew up with TSS, their gender identity is non-binary. At the start of the series they don't know whether they're attracted to anyone, but want to find out with Ryou's help and, unsurprisingly, they're into Ryou in both forms. Ryou is more comfortable being in his male form and thinks he would like to stop switching, but he's flexible about it in practice and he's also not got a problem with finding Nagisa's male form attractive. The male x male state gets less page time, but it's not given a hard swerve.
Most of the secondary characters are from the cosplay cafe, including Kai, a trans man, Ichika, a lesbian who is dating the cafe owner, and Rui, a crossdressing boy. It's reminiscent of Fukakai na Boku no Subete o, but a lighter treatment of the territory. The TSF love comedy is the focus and the cosplaying is useful for fanservice.
The mangaka has a background in ero manga and Teens Love, but this isn't a series that goes very far with its sexual content. They're still drawing doujin stuff of the couple, but seemingly not adult rated.